1. Field of the Invention
The invention relates generally to acceleration/deceleration circuits for generating stepping pulses for stepper motors and more particularly to an acceleration/deceleration circuit which is time independent and provides optimum acceleration and deceleration.
2. Description of the Prior Art
Stepper motors are widely used for discrete positioning control and there are numerous applications for discrete positioning. Many applications require moving thousands of steps from one position to another. One way of achieving this would be to stop after each pulse before providing the next pulse to the stepper motor. This would insure that no loss of steps occurs. However, the disadvantage is that this method of stepping is very slow.
An alternative method to move from one position to another involves accelerating the rate of pulses, without stopping between pulses, to reach a maximum pulse rate and then to decelerate the pulse rate so that the stepper motor stops at the desired position. This method of pulsing is referred to as slewing. However, if the rate of acceleration or deceleration of pulses is too great, steps will be missed resulting in the final position of the stepper motor being incorrect.
There are numerous techniques for acceleration/deceleration of stepper motors. Some of these techniques are described in the proceedings of the Seventh Annual Symposium on Incremental Motion Control Systems and Devices, 1978, pages B-29 through B-39.